What might cause an IAP purchase to fail?

Question

Unity

I made a purchase in the editor and checked, everything is rejected and a successful purchase goes through, all windows work properly, I uploaded it to Google, and I installed it through Google and I try to pay, the window appears as if there was a payment error right away, it doesn’t even try to call the card selection there, etc. .d.
In the google console, this application is in internal testing, maybe because of this?
But in closed testing, wait another day until it is approved ...
What could be the problem if everything works fine in the editor, the purchase in Google and the template installed everything as it should ...
How to check what the problem is?

Answer 1

It’s not at all clear what you checked in the editor, Google can’t check it for sure.
To check, they make a debug build (in case it doesn’t work) and check purchases from under the test account, since they are free.